<!doctype html>
<html>
  <head>
    <title>Socket.IO chat</title>
    <style>
      * { margin: 0; padding: 0; box-sizing: border-box; }
      body { font: 13px Helvetica, Arial; }
      form { background: #000; padding: 3px; position: fixed; bottom: 0; width: 100%; }
      form input { border: 0; padding: 10px; width: 90%; margin-right: .5%; }
      form button { width: 9%; background: rgb(130, 224, 255); border: none; padding: 10px; }
      #messages { list-style-type: none; margin: 0; padding: 0; }
      #messages li { padding: 5px 10px; }
      #messages li:nth-child(odd) { background: #eee; }
    </style>
  </head>
  <body>
    <ul id="messages"></ul>
    <form action="">
      <input id="m" autocomplete="off" /><button>Send</button>
    </form>
  </body>
  <script src="/socket.io/socket.io.js"></script>
<script src="https://code.jquery.com/jquery-1.11.1.js" rel="external nofollow" ></script>
<script>
  $(function () {
    var socket = io();
    socket.emit("UserLogin",'user'+ Date.now())
    $('form').submit(function(){
      // chat message 跟后端沟通的自定义事件名 自定义就行 只要前后端一致就行  
      socket.emit('chatRoom',`{
          name: "对方",
          content:
            "老子上单无敌，好烦~~~~~~",
          img: "https://www.hualigs.cn/image/60364a03036ce.jpg",
          tag: 0,
        }`);
      return false;
    });
    socket.on('chatRoom', function(msg){
      $('#messages').append($('<li>').text(msg));
    });
  });
</script>
</html>